Spectacle Hinge Carriage With Spring Cavity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flexible hinges for spectacles face issues with material usage, torsional strength, and wear due to the placement and sizing of helical springs, leading to inefficiencies in guiding and elastic behavior.
Innovation Solution
A flexible hinge design featuring a U-shaped carriage with parallel bars forming elongated openings to securely house and guide an elastic element, minimizing material usage while enhancing torsional stability and reducing wear through precise angular and cross-sectional design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the helical spring is fitted on a cylindrical pin of the carriage, then the spring is supported in the correct working position and the distal end constraint is provided, but the pin represents a weak support structure and requires additional material for structural strength
Solution Approach 1:
The invention removes the weak support pin from the carriage structure entirely. Instead of fitting the spring on a cylindrical pin, the spring is directly contained within a cavity of the carriage body, eliminating the need for the pin while maintaining spring positioning reliability through the cavity geometry and retaining clip mechanism.
Solution Approach 2:
The carriage body cavity serves multiple functions simultaneously: it houses the spring, provides structural support, ensures proper spring positioning, and eliminates the need for separate support pins. The retaining clip also serves dual purposes by constraining the spring's proximal end while maintaining the elastic response.
2Strength
If the carriage is obtained as a U-bent element with two side legs, then the system gains torsional stiffness, but the overall lateral bulk is increased by the width of the helical spring and thickness of side walls
Solution Approach 1:
Instead of making the entire carriage body thick and massive to achieve torsional stiffness, the invention applies material strategically at critical locations. The carriage body has a U-shaped profile with optimized wall thicknesses that provide sufficient torsional stiffness only where needed, while minimizing overall lateral bulk. The cavity geometry is locally optimized to house the spring without requiring excessive material.
Solution Approach 2:
The invention transitions from a two-dimensional U-shaped profile to a three-dimensional cavity structure within the carriage body. This allows the spring to be housed in a dedicated cavity space, separating the spring housing function from the structural support function, thereby reducing the need for increased lateral bulk while maintaining torsional stiffness.
3Ease of operation
If the spring is housed in the carriage with a wide gap and constrained solely along two opposite diameter lines, then the spring is freely housed, but the spring tends to move transversally during compression and extension phases causing wear or non-linear elastic behavior
Solution Approach 1:
The invention introduces asymmetric constraints on the spring by positioning the retaining clip at a specific location and orientation within the carriage cavity. This asymmetric arrangement provides controlled guidance to the spring during compression and extension, preventing transverse movement and ensuring consistent elastic behavior while maintaining the freedom of the spring to perform its elastic response.
Solution Approach 2:
The retaining clip acts as an intermediary element between the spring and the carriage cavity. It provides precise positioning and guidance to the spring, preventing transverse movement and ensuring linear elastic behavior, while still allowing the spring to freely expand and contract along its longitudinal axis. The clip mediates between the need for freedom of movement and the need for consistent elastic response.
4Device complexity
If the longitudinal guiding of the carriage is ensured solely by the engagement between the edges of the U profile and the inner surfaces of the housing body, then the structure is simple, but acceptable tolerances leave a certain torsional clearance of the carriage in the housing body
Solution Approach 1:
The invention segments the guiding function into multiple contact points and surfaces. Instead of relying on a single engagement between U-profile edges and housing inner surfaces, the carriage cavity geometry provides multiple guidance surfaces that work together with the housing body to constrain torsional clearance. This segmentation allows for more precise guiding while maintaining manufacturing feasibility.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves high-strength, cost-effective flexible hinges with improved torsional guidance and reduced material usage, minimizing wear and ensuring precise elastic behavior.
Implementation Method 1
an elastic element being provided and constrained between a distal-end base of the carriage and retaining means which can be coupled with said sliding cavity and apt to cause an elastic reaction which contrasts the withdrawal of said carriage from the housing
Implementation Method 2
The sliding movement of the carriage causes a compression of the spring (constrained on one side to the fixed box body and on the other side to the movable end of the carriage) which hence imparts the desired elastic reaction
Data Source
Figure 1~3
Figure 4A~5
Figure 6~7B
AI summary
A flexible hinge for spectacles is disclosed, of the type comprising a female component (7) mutually articulated with a male component (1, 1', 2), the latter one having at least one housing (1), forming a sliding cavity, and a carriage (2) sliding in said housing (la), generally U-shaped and provided with two terminal eyelet-shaped heads (2b) defining a hinge axis, a longitudinally-arranged elastic element ( 4 ) being furthermore provided, constrained between a distal end base of the carriage (2) and retaining means (5) which can be coupled with said sliding cavity (la) and apt to produce an elastic reaction which contrasts the withdrawal of said carriage from the housing (1, 1"), wherein the carriage (2) is shaped according to two U- shaped structures (2e, 2d), each one comprising two parallel bars, connected to said distal end base (2a) of the carriage and to said two eyelet-shaped heads (2b), said U-shaped structures (2e, 2d) being combined on the same main portion of the carriage body so as to arrange said parallel bars along four longitudinal corner edges of the carriage and thereby forming elongated, lateral, upper and lower openings.